chore(run.sh): keep cargo build output out of server.log / schema_service.log

[shiba4life]

Summary

cargo run re-emits compiler progress + warnings on stderr, so the existing nohup cargo run ... > server.log 2>&1 & pattern in run.sh dumped "Compiling/Finished/Running" lines (and any rustc warnings — e.g. the macOS-only dead_code warning on build_attendee_ingestion_records) into the log file the in-app LogSidebar reads. The first ~12 lines of every fresh run.sh server.log were build chatter, not server output, and the UI rendered them as if they were runtime tracing.

Fix: build first (output → stderr, visible in the user's terminal), then exec the freshly built binary directly with stdout/stderr captured to the log file. Same shape applied to the local schema service path so schema_service.log is also clean.

Before

$ head -15 \"\$FOLDDB_HOME/server.log\"
warning: function \`build_attendee_ingestion_records\` is never used
   --> src/server/routes/apple_import.rs:801:4
    |
801 | fn build_attendee_ingestion_records(
    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: \`#[warn(dead_code)]\` (part of \`#[warn(unused)]\`) on by default

warning: \`fold_db_node\` (lib) generated 1 warning
    Finished \`dev\` profile [unoptimized + debuginfo] target(s) in 0.36s
     Running \`target/debug/folddb_server --port 9102 --schema-service-url 'http://127.0.0.1:9103'\`
FoldDB Server (config file detected)
...

After

$ head -5 \$FOLDDB_HOME/server.log
FoldDB Server (config file detected)
  Data:   /tmp/test-runlog-cleanlogs/data
  Schema: http://127.0.0.1:9103
  UI:     http://localhost:9102
  Logs:   /tmp/test-runlog-cleanlogs/observability.jsonl

$ head -5 \$FOLDDB_HOME/schema_service.log
🚀 Schema service starting with local sled storage
   Database path: /tmp/test-runlog-cleanlogs/schema_registry
✅ Schema service listening on 127.0.0.1:9103

The compiler dead_code warning is left alone — it's tracked separately as a known macOS-local clippy noise. The point of this PR is keeping log files clean regardless of any warnings rustc emits.

Test plan

• bash -n run.sh passes
• Cold (clean target) ./run.sh --local --local-schema --empty-db --home /tmp/test-runlog-cleanlogs — both services come up healthy, head -5 on both logs shows server tracing only, no compiler output
• Warm (cached target) restart — same clean output, both services healthy on auto-slotted ports (9102/9103)
• curl http://127.0.0.1:9102/api/system/status and curl http://127.0.0.1:9103/v1/health return 200

🤖 Generated with Claude Code